Generally, Universal Serial Bus (USB) is a serial bus standard to the PC architecture with a focus on computer interface, consumer and productivity applications. The existing Universal Serial Bus (USB) interconnects have the attributes of plug-and-play and ease of use by end users. Now, as technology innovation marches forward, new kinds of devices, media formats and large inexpensive storage are converging. They require significantly more bus bandwidth to maintain the interactive experience that users have come to expect. In addition, the demand of a higher performance between the PC and the sophisticated peripheral is increasing. The transmission rate of USB 2.0 is insufficient. As a consequence, faster serial bus interfaces such as USB 3.0, are developed, which may provide a higher transmission rate so as to satisfy the need of a variety devices.
An existing USB electrical plug connector includes a shell, an insulated housing, and a plurality of transmission terminals. The transmission terminals are assembled in the insulated housing, and the shell encloses the insulated housing. When the USB electrical plug connector is mated with a USB electrical receptacle connector, one side of the insulated housing is inserted into the USB electrical receptacle connector, so that the transmission terminals are in contact with the receptacle terminals inside the USB electrical receptacle connector. Therefore, signals can be transmitted between the plug connector and the receptacle connector.
However, the shell covers the front of the insulated housing, but not the rear of the insulated housing. Therefore, a base portion of the insulated housing is exposed from the rear of the insulated housing. In addition, the USB electrical plug connector further includes a circuit board assembled at the bottom of the base portion, and the end portions of the transmission terminals are soldered with the circuit board. Commonly, the end portions of the transmission terminals would be departed from the circuit board easily when the USB electrical plug connector is bent, during the USB electrical plug connector is plugged into or departed from the USB electrical receptacle connector. In other words, the rear of the insulated housing is devoid of a structure for positioning with the circuit board, so that the bending resistance between the circuit board and the insulated housing is less sufficient.